Skin lite cream burn my face. My age 20!

The quantity of skin light cream that you are applying is probably more which is causing redness and irritation. You need to use less quantity of the cream. Also give it a break for a couple of days till the irritation and inflammation subsides. The darkening of skin can be multiple causes like tanning, vitamin B12 deficiency, addisonian pigmentation, acanthosis nigricans, lichen planus pigmentosus, rhiel's melasnosis or several other causes. A proper assessment and examination will help ascertain the proper cause. For loss of glow & dullness - there are antioxidant therapies like glutathione , lasers for rejuvenation, PRP therpy for facial rejuvenation , peels, etc. Kojic acid alone is safe but less effective. The BEST cream would depend upon the cause. Get an online consult or meet a dermatologist directly for a proper evaluation of the condition. Hope this was helpful.